BERWILIT - WITTGENSTEINER BLÄHSCHIEFER GMBH

BERWILIT - Wittgenstein Blähschiefer GmbH is a producer of expanded slate lightweight aggregate located in Bad Berleburg, Germany. The raw material is natural roofing slate extracted from the nearby Raumland Böhl quarry. Geologically, this Wittgensteiner slate belongs to the Rheinisches Schiefergebirge and was formed roughly 380 million years ago. As a sedimentary rock containing organic constituents, its composition closely resembles clay, which is why it is also called clay slate. Originally, spoil heaps from roofing slate operations supplied the feedstock. During processing, rising internal pressure caused by heat drives off air and organic matter; the grain expands, developing a porous interior with closed pores and a dense, sintered outer shell. The aggregate serves in lightweight concrete, fire-resistant lightweight concretes up to 1100°C, sound and thermal insulation fillings, and screed panels.